fix(hmr): fix render error in change static nodes (vuejs#6978)

packages/runtime-core/__tests__/hmr.spec.ts

@@ -20,7 +20,7 @@ const { createRecord, rerender, reload } = __VUE_HMR_RUNTIME__
 registerRuntimeCompiler(compileToFunction)
 
 function compileToFunction(template: string) {
-  const { code } = baseCompile(template)
+  const { code } = baseCompile(template, { hoistStatic: true })
   const render = new Function('Vue', code)(
     runtimeTest
   ) as InternalRenderFunction
@@ -536,4 +536,32 @@ describe('hot module replacement', () => {
     render(h(Foo), root)
     expect(serializeInner(root)).toBe('bar')
   })
+
+  test('rerender in change hoisted nodes', () => {
+    const root = nodeOps.createElement('div')
+    const appId = 'test-app-id'
+    const App: ComponentOptions = {
+      __hmrId: appId,
+      render: compileToFunction(
+        `<div v-for="item of 2"><div>1</div></div><p>2</p><p>3</p>`
+      )
+    }
+    createRecord(appId, App)
+
+    render(h(App), root)
+    expect(serializeInner(root)).toBe(
+      `<div><div>1</div></div><div><div>1</div></div><p>2</p><p>3</p>`
+    )
+
+    // move the <p>3</p> into the <div>1</div>
+    rerender(
+      appId,
+      compileToFunction(
+        `<div v-for="item of 2"><div>1<p>3</p></div></div><p>2</p>`
+      )
+    )
+    expect(serializeInner(root)).toBe(
+      `<div><div>1<p>3</p></div></div><div><div>1<p>3</p></div></div><p>2</p>`
+    )
+  })
 })

packages/runtime-core/src/vnode.ts

@@ -39,7 +39,7 @@ import {
 } from './componentRenderContext'
 import { RendererNode, RendererElement } from './renderer'
 import { NULL_DYNAMIC_COMPONENT } from './helpers/resolveAssets'
-import { hmrDirtyComponents } from './hmr'
+import { hmrDirtyComponents, isHmrUpdating } from './hmr'
 import { convertLegacyComponent } from './compat/component'
 import { convertLegacyVModelProps } from './compat/componentVModel'
 import { defineLegacyVNodeProperties } from './compat/renderFn'
@@ -423,6 +423,12 @@ function createBaseVNode(
   isBlockNode = false,
   needFullChildrenNormalization = false
 ) {
+  // #6978 the children maybe a hoisted array that should be cloned
+  // since it maybe changed during HMR
+  if (__DEV__ && isHmrUpdating && isArray(children)) {
+    children = [...children]
+  }
+
   const vnode = {
     __v_isVNode: true,
     __v_skip: true,